Original air date: 11/8/2001
Production code: 3ACX-01
After helping Lois's sister Carol (who was recently abandoned by her husband) deliver her baby, Peter and Lois decide to have another kid. Stewie is outraged that he'll no longer be the baby of the family and vows to prevent them from conceiving. After many failed attempts to stop the two, Stewie shrinks himself down to microscopic size so he can travel inside Peter and destroy every sperm cell in his body.
This episode contains examples of:
- Adam Westing: Majel Barrett voices the computer on Stewie's ship, as in so many Starfleet vessels in Star Trek.
- Artistic License – Biology: Sperm as People aside, the most Stewie would accomplish by destroying the sperm cells directly is to delay the fertilization process for a while until Peter's troops recover to acceptable numbers. If he really wanted to do damage to the Griffin's fertility, he would have to find a way to stop the sperm production process itself, or enter Lois' body and destroy her egg cells since those cannot be regenerated unlike sperm.
- Baby Fever Trigger: Helping Lois's sister Carol give birth makes Peter want to have another baby. His initial instinct is to just steal Carol's baby, but instead concedes to try and conceive with Lois again, kicking off the episode's plot.
- Big "WHAT?!": Stewie's Delayed Reaction to learning Peter and Lois want to have another baby.
- Brick Joke: Upon finding his old pet rock, Peter recalls the day they brought it home: it peed on the carpet. Later during his romantic evening with Lois, Peter plays the guitar and cues the rock for a solo, only for it to pee again.
- Comically Missing the Point: While driving Carol to the hospital, Peter takes a detour to pick up some drive-thru. Lois yells at him, since her sister is currently in labour. However, Peter thinks Lois wants him to get something for the baby too and decides to order a kid's meal.
- Companion Cube: Peter's pet rock, which is somehow able to pee on the carpet (twice).
- Constructive Body Disposal: Stewie's Imagine Spot montage of what life with his prospective little brother Bertram would be like revolves around them teaming up to take down Lois, with the last one depicting them burying her in cement.
- Cousin Oliver: Stewie dreads a new baby will lead to him being replaced, even citing The Brady Bunch. A cutaway then shows the Bradys fawning over Oliver and mistreating Bobby.Bobby: [entering] Hey, everybody, I—
Mike: Bobby! You get back in the garage! [jabs him with the broom] - Drive-Thru Antics: Peter stops at a window while driving Lois and her pregnant sister Carol, who is in labor.Peter: Um, yeah, I'll have three cheeseburgers.
Lois: Peter, for God's sakes, she's having a baby!
Peter: Oh, that's right. A-And a kids meal. And, uh...I-I guess I'll have fries. If I have fries, is anyone gonna have any? 'Cause, you know, I don't wanna be the only one eating them. I'll feel like a fatty. - Erotic Eating: Peter and Lois seductively feed fruit to each other as foreplay, but Peter ruins the moment when he shoves a slice of watermelon down Lois' throat.
- "Fantastic Voyage" Plot: Stewie travels inside Peter's body to destroy his sperm cells, which are depicted as ships piloted by babies like him.
- Idiot Ball: Stewie could have easily gotten away with framing Lois for getting lipstick all over Peter's favorite shirt if he just left the bathroom, but he just had to stay and admire himself in the mirror with the lipstick still on him, which caused Lois and Brian to stumble on the scene and prevent his Frame-Up from happening.
- Instant Sedation: Played comically straight when Stewie commandeers a robotic Peter lookalike to stop him from having sex with Lois. To get Peter out of the way, Stewie lures him out of the bedroom with beer before shoving a chloroform-soaked cloth in his face. It takes all of one second for Peter to be out like a light.
- Invasion of the Baby Snatchers: Mentioned briefly after Carol's baby is born, and Lois comments on how sweet Peter looked holding the infant.Peter: I know, I just didn't want to let it go!Lois: Really?Peter: Let's steal it.Lois: What?!
- Manly Tears: So the former can escape through the tear ducts, Stewie and Bertram get Peter to cry by singing "Up Where We Belong." It works.Lois: [seeing Peter tear up] Oh, Peter, I love you.
Peter: And I love you, Lou Gossett, Jr. - "Not So Different" Remark: Stewie and Bertram bond over having similar viewpoints, one of which is wanting to kill Lois.
- Obnoxious In-Laws: Actually averted with Peter and Carol! Not only do they speak kindly to each other even when Peter jokes that he's Carol's estranged husband coming back (which gets a chuckle out of Carol), he's the one who helps deliver her son.
- Oh, Crap!: Stewie is relieved that Bertram survived Peter's bathroom trip, calling him quite clever. He then worries that his would-be brother is "too clever."
- Ow, My Body Part!: While in transit inside Peter's body, Stewie needs to buy some time before Peter and Lois get it on, leading him to fire at Peter's duodenum (the entry point between the stomach and the small intestine). This immediately prompts Peter to claim with remarkable specificity "Oh jeez, my duodenum's acting up!" before bolting to the bathroom.
- Parental Favoritism: Chris was conceived because of a broken condom, which resulted in a lawsuit that paid for the Griffin's house. Because of this, Lois refers to Chris as her favorite mistake, which he lords over Meg.
- Skewed Priorities: Peter stops off at a drive-thru while driving Carol to the hospital as she's in labor.
- Sperm as People: The sperm inside Peter are all presented as Space Fighters. Interestingly, in a weird bout of Continuity Nod, it lines up with Stewie's own self-described experiences mentioned back in Season One.
- Stealth Insult: "You're my favorite mistake."
- That's What She Said: While Peter and Brian are assembling a crib:Brian: Okay, insert rod support A into slot B.Peter: [giggling] That's what she—Brian: If you say "that's what she said" one more time, I'm gonna pop you.
- Urine Trouble: Courtesy of a pet rock.Peter: Bad rock! Bad! We do that outside!
- Worthy Opponent: Both Stewie and Bertram refer to each other as this.Stewie: It's going to be a shame to destroy such a worthy adversary.Bertram: My thoughts exactly.
